Supporters of a Kyrgyz MP killed during a prison visit last week have been calling for the resignation of the prime minister, Felix Kulov.

They are suggesting Mr Kulov is somehow linked to the shooting.

But Mr Kulov's supporters point out that the man making the accusations, the dead MP's brother, himself faces charges of ordering a mafia-related murder.

For many people, the murky affair of Tynchbek Akmatbayev's killing is evidence of an alarming growth in the influence of Kyrgyzstan's criminal mafia.

The politicisation of the affair by the dead man's brother, Rysbek, is widely seen as an attempt to discredit Prime Minister Kulov, a politician who gained considerable popularity as a focus of opposition to the authoritarian regime of former president Askar Akayev.

Camp of yurts

Mr Kulov was imprisoned during the Akayev period on charges of political and financial abuse which have now been recognised as false.

Mr Kulov's supporters believe the protests are politically motivated

But his time in prison was spent at the same Moldovanovka prison, outside the capital Bishkek, where MP Tynchbek Akmatbayev was shot dead during a visit last week.

The dead MP's brother, Rysbek, claims the shooting was done by a criminal gang leader who was an associate of Felix Kulov when he was in prison.

Rysbek has organised a camp of yurts outside parliament calling for the prime minister's resignation.

But Mr Kulov strongly denies any connection with the shooting. He and his supporters in the Ar-Namys party say the Akmatbayev brothers themselves have criminal links, and that Tynchbek's murder was simply a settling of scores between rival gangs.

The prime minister's supporters question why Rysbek Akmatbayev should accuse Felix Kulov so directly of involvement in the killing.

They suggest he has been prompted by powerful political rivals seeking to discredit Mr Kulov and prevent him gaining his ultimate goal, the presidency.

Many Kyrgyz citizens fear the affair could threaten the current political equilibrium, established after Mr Akayev's was ousted, when Mr Kulov conceded the presidency to one of his rivals, Kurmanbek Bakiev, on condition he was given the premiership.

That agreement, many believe, is the best way of guaranteeing political stability in the immediate future.

There is also increasing concern that the forces of law and order have apparently been making concessions to people with known criminal connections, and have not moved against the demonstrators camped outside parliament.

The influence of criminal organisations is now so strong, some people believe, that politicians and even the police are afraid to take action against them.